public class Persian Tools ; IPersian Math , IPersian Text

}

; public int Sum ( int a , int b) => a + b      

;public int Sum ( int a , int b , int c ) = a + b + c      

; ()public string ReverseText (string txt) => new string (txt.ToCharArray() . Reverse() . ToArray      

; { public string Postfix ( string txt , string Postfix) => $ " { txt } { Postfix      

; { public string Pertfix ( string txt , string Perfix) => $ " { perfix } { txt      

{

public class CustomTools : IPersian Math

}

;  ( public int Sum ( int a , int b) => 2 * ( a+ b       

; ( public int Sum ( int a , int b , int c ) => 3* ( a + b + c       

{